He is best known for helping Hawaii in gaining recognition from Britain, France, and the United States as an independent sovereign nation.

Jean Baptiste Rives who had served as Kamehameha II's secretary had been accused of mismanagement of funds and never returned to Hawaii.

Captain Cyrille Pierre Théodore Laplace described him as: The king's secretary and one of his favorites was a handsome young man of frank, pleasant countenance and good manners; he wore European dress and spoke English quite well.

[8]He was a member of the hulumanu (bird feathers), a group of often flamboyant favorites of King Kamehameha III that originally included Kamehamea IIIʻs aikāne (intimate friend) Kaomi Moe[9] In the 1840 Constitution of the Kingdom of Hawaii, he was included in the first members of the House of Nobles.

[6]: 367 In London they met up with Sir George Simpson of the Hudson's Bay Company and requested a visit with Lord Aberdeen who was British Secretary of State for Foreign Affairs.

Confident in their success, Sir George Simpson returned to Canada, thinking Richards and Haʻalilo could wrap up the details through April and May 1843.

[15] They returned to America, and visited the new Secretary of State John C. Calhoun who was invited to also sign the agreement, but said he would wait for a treaty that could be ratified by the Senate.

They left Boston November 18, 1844, on the ship Montreal, but Haʻalilio's health declined, and he died December 3, 1844, off the coast of New York.

[6]: 398 Bingham offered this praise: Haalilio was a man of intelligence, of good judgement, of pleasing manners, and respectable business habits.